python 数据类型：整型字符串布尔值列表元组字典集合

不可变类型：整型字符串整型字符串

可变类型：列表字典

一、列表常用命令

#增删改查
#查切片 []

# print(a[1:])#取到最后
# print(a[1:-1])#取到倒数第二值
# print(a[1:-1:1])#从左到右一个一个去取
# print(a[1::2])#从左到右隔一个去取
# print(a[3::-1])
# b=a[3::-1]
# print(b)#['sanpang', 'xiaohu', 'jinxin', 'wuchao']
# print(a[-2::-1])
# print(a[1:-1:-2])

#添加 append insert

# a.append('xuepeng') #默认插到最后一个位置
# print(a)
# a.insert(1,'xuepeng') #将数据插入到任意一个位置
# print(a)

#修改
#
# a[1]='haidilao'
# print(a)
# a[1:3]=['a','b']
# print(a)

#删除 remove pop del

# a.remove(a[0])
# print(a)
# b=a.pop(1)
# print(a)
# print(b)
#
# del a[0]
# print(a)
# del a
# print(a)
# a.remove(['wuchao','jinxin'])
# print(a)

#count:计算某元素出现次数
# t=['to', 'be', 'or', 'not', 'to', 'be'].count('to')
# print(t)

#extend
# a = [1, 2, 3]
# b = [4, 5, 6]
# a.extend(b)
# print(a)
# print(b)

# index # 根据内容找位置

# a = ['wuchao', 'jinxin', 'xiaohu','ligang', 'sanpang', 'ligang', ['wuchao', 'jinxin']]
#
#
# first_lg_index = a.index("ligang")
# print("first_lg_index",first_lg_index)
# little_list = a[first_lg_index+1:]
#
# second_lg_index = little_list.index("ligang")
# print("second_lg_index",second_lg_index)
#
# second_lg_index_in_big_list = first_lg_index + second_lg_index +1
#
# print("second_lg_index_in_big_list",second_lg_index_in_big_list)
# print("second lg:",a[second_lg_index_in_big_list])

# reverse 反转列表内容

# a = ['wuchao', 'jinxin', 'xiaohu','ligang', 'sanpang', 'ligang']
# a.reverse()
# print(a)

#sort 列表排序

# x = [4, 6, 2, 1, 7, 9]
# x.sort(reverse=True)
# print(x)#[1, 2, 4, 6, 7, 9]

a = ['wuchao', 'jinxin', 'Xiaohu','Ligang', 'sanpang', 'ligang']
# a.sort()
# print(a)

print(a.count("haidilao ge"))
print(a.pop())
print(a)

二、元组常用命令与列表类似区别是列表是可变类型元组是不可变类型

#dic={1:'alex','age':35,'hobby':{'girl_name':'铁锤','age':45},'is_handsome':True}
# dic={'age':'alex','age':35,'hobby':{'girl_name':'铁锤','age':45},'is_handsome':True}

# print(dic)

#字典两大特点：无序，键唯一

三、字典常用命令

#字典的创建
# a=list()
# print(a)

# dic={'name':'alex'}

# dic1={}
# dic2=dict((('name','alex'),))
# print(dic2)

# dic3=dict([['name','alex'],])
# print(dic3)

#字典修改
# dic1={'name':'alex'}
# dic1['age']=18
# print(dic1)

#键存在，不改动，返回字典中相应的键对应的值
# ret=dic1.setdefault('age',34)
# print(ret)
#
# #键不存在，在字典中中增加新的键值对，并返回相应的值
# ret2=dic1.setdefault('hobby','girl')
# print(dic1)
# print(ret2)

#字典查通过键去查找
# dic3={'age': 18, 'name': 'alex', 'hobby': 'girl'}
#
# print(dic3['name'])
#
# print(list(dic3.keys()))
# print(list(dic3.values()))
# print(list(dic3.items()))

# li=[1,2,34,4]
# li[2]=5
# dic3={'age': 18, 'name': 'alex', 'hobby': 'girl'}
# dic3['age']=55
# print(dic3)

# dic4={'age': 18, 'name': 'alex', 'hobby': 'girl'}
# # dic5={'1':'111','2':'222'}
# dic5={'1':'111','name':'222'}
#
# dic4.update(dic5)
# print(dic4)
# print(dic5)

#字典删除

# dic5 = {'name': 'alex', 'age': 18, 'class': 1}

# dic5.clear() # 清空字典
# print(dic5)
# del dic5['name'] #删除字典中指定键值对
# print(dic5)

# print(dic5.pop('age')) #删除字典中指定键值对，并返回该键值对的值
# ret=dic5.pop('age')
# print(ret)
# print(dic5)

# a = dic5.popitem() #随机删除某组键值对，并以元组方式返回值
# print(a, dic5)

# del dic5 #删除整个字典
# print(dic5)

#5 其他操作以及涉及到的方法

# dic6=dict.fromkeys(['host1','host2','host3'],'test')
# print(dic6)#{'host3': 'test', 'host1': 'test', 'host2': 'test'}
#
# dic6['host2']='abc'
# print(dic6)

# dic6=dict.fromkeys(['host1','host2','host3'],['test1','tets2'])
# print(dic6)#{'host2': ['test1', 'tets2'], 'host3': ['test1', 'tets2'], 'host1': ['test1', 'tets2']}
#
# dic6['host2'][1]='test3'
# print(dic6)#{'host3': ['test1', 'test3'], 'host2': ['test1', 'test3'], 'host1': ['test1', 'test3']}

# av_catalog = {
# "欧美":{
# "www.youporn.com": ["很多免费的,世界最大的","质量一般"],
# "www.pornhub.com": ["很多免费的,也很大","质量比yourporn高点"],
# "letmedothistoyou.com": ["多是自拍,高质量图片很多","资源不多,更新慢"],
# "x-art.com":["质量很高,真的很高","全部收费,屌比请绕过"]
# },
# "日韩":{
# "tokyo-hot":["质量怎样不清楚,个人已经不喜欢日韩范了","听说是收费的"]
# },
# "大陆":{
# "1024":["全部免费,真好,好人一生平安","服务器在国外,慢"]
# }
# }

# av_catalog['欧美']["www.youporn.com"][1]='高清午马'

dic={5:'555',2:'666',4:'444'}
# dic.has_keys(5)
# print(5 in dic)
# print(sorted(dic.items()))
# dic5={'name': 'alex', 'age': 18}

# for i in dic5:
# print(i,dic5[i])+

# for i,v in dic5.items():
# print(i,v)

四、String 操作

# a="Let's go "
# print(a)
# 1 * 重复输出字符串
# print('hello'*20)

# 2 [] ,[:] 通过索引获取字符串中字符,这里和列表的切片操作是相同的,具体内容见列表
# print('helloworld'[2:])

#关键字 in
# print(123 in [23,45,123])
# print('e2l' in 'hello')

# 4 % 格式字符串
# print('alex is a good teacher')
# print('%s is a good teacher'%'alex')

#5
# a='123'
# b='abc'
# d='44'
# # # c=a+b
# # # print(c)
# #
# c= ''.join([a,b,d])
# print(c)

五、String的内置方法

# st='hello kitty {name} is {age}'
#
# print(st.count('l')) # 统计元素个数
# print(st.capitalize()) # 首字母大写
# print(st.center(50,'#')) # 居中
# print(st.endswith('tty3')) # 判断是否以某个内容结尾
# print(st.startswith('he')) # 判断是否以某个内容开头
# print(st.expandtabs(tabsize=20))
# print(st.find('t')) # 查找到第一个元素，并将索引值返回
# print(st.format(name='alex',age=37)) # 格式化输出的另一种方式待定：?:{}
# print(st.format_map({'name':'alex','age':22}))
# print(st.index('t'))
# print('asd'.isalnum())
# print('12632178'.isdecimal())
# print('1269999.uuuu'.isnumeric())
# print('abc'.isidentifier())
# print('Abc'.islower())
# print('ABC'.isupper())
# print(' e'.isspace())
# print('My title'.istitle())
# print('My tLtle'.lower())
# print('My tLtle'.upper())
# print('My tLtle'.swapcase())
# print('My tLtle'.ljust(50,'*'))
# print('My tLtle'.rjust(50,'*'))
# print('\tMy tLtle\n'.strip())
# print('\tMy tLtle\n'.lstrip())
# print('\tMy tLtle\n'.rstrip())
# print('ok')
# print('My title title'.replace('itle','lesson',1))
# print('My title title'.rfind('t'))
# print('My title title'.split('i',1))
# print('My title title'.title())

#摘一些重要的字符串方法
#1 print(st.count('l'))
# print(st.center(50,'#')) # 居中
# print(st.startswith('he')) # 判断是否以某个内容开头
# print(st.find('t'))
# print(st.format(name='alex',age=37)) # 格式化输出的另一种方式待定：?:{}
# print('My tLtle'.lower())
# print('My tLtle'.upper())
# print('\tMy tLtle\n'.strip())
# print('My title title'.replace('itle','lesson',1))
# print('My title title'.split('i',1))

集合

作用对元素去重以及关系测试

1 in ,not in

2 集合等价与不等价（==，!=）

3 子集、超集

s=set('skywqq')

s1=set('sky')

print('s' in s)

print(s1<s)

s.add('op') 添加一个元素op

s.update('op') 添加两个元素 o p

s.remove('i') 删除元素 i

del 删除整个集合

a=set([1,2,3,4,5])
b=set([4,5,6,7,8])#交集 intersection和 &
print(a.intersection(b))   #{4, 5}
print(a & b)               #{4, 5}#并集 union和 |
print(a.union(b))    #{1, 2, 3, 4, 5, 6, 7, 8}
print(a | b)          #{1, 2, 3, 4, 5, 6, 7, 8}#差集 diffrent和-
print(a.difference(b))  #a有的b没有   {1, 2, 3}
print(a-b)               #{1, 2, 3}
print(b.difference(a))  #b有的a没有   {8, 6, 7}
print(b-a)              #{8, 6, 7}#对称差集 反向交集和^
print(a.symmetric_difference(b))   #{1, 2, 3, 6, 7, 8}
print(a^b)                        #{1, 2, 3, 6, 7, 8}#父集
print(a.issuperset(b))  #False
#子集
print(a.issubset(b))    #False

六、字符串占位符：

%s s=string 字符串

%d d=digit 整数

%f f=float 浮点数

1、字符串格式化输出

# _author:"Sky"
# date:2022/8/1name=input("name:")
age=int(input("age:"))
job=input("job:")
salary=input("salary:")if salary.isdigit():           #判断是不是整数salary=int(salary)
else:exit("must input digit")msg='''
.........info of %s.........
Name:%s
Age:%d
Job:%s
Salary:%f
you will be retired in %s years
............end................
'''%(name,name,age,job,salary,60-age)print(msg)

七、python 实现简单购物车

八、python实现三级菜单

region={'河南省':{"周口市":{"扶沟县":["江村镇","包屯镇"],"商水县":["黄寨镇","练集镇"],"郸城县":["吴台镇","南丰镇"],"商丘县":["城关镇"]},"开封市":["兰考县","通许县","尉氏县"],"郑州市":["新政","登封","巩义"]},'福建省':{"三明市":["清流县","大田县","建宁县"],"厦门市":["思明","湖里","集美"]},'广东省':{"广州市":["天河","黄埔","白云"],"佛山市":["三水","南海","顺德"]}
}

九、python 编码解码

python2里默认是ascii码，转换如下：

decode是解码 encode是编码

python3里默认是unicode，，python3得encode是编码得同时转为bytes类型。。decode是在解码得同时同时将bytes转为字符串。

十、深浅拷贝

# _author:"Sky"
# date:2022/8/17
import copy
import shallow_deep_copy#浅拷贝
a=["sky",2,3,[100,800]]
shallow_copy=a.copy()
shallow_copy[0]="wqq"
shallow_copy[1]=222
shallow_copy[3][1]-=30
print(a)
print(shallow_copy)#深拷贝
dep_copy=copy.deepcopy(a)
dep_copy[0]="cjc"
dep_copy[1]=888
dep_copy[3][1] -=10
print(a)
print(dep_copy)